The character Rayden is called Raiden in this game
The two female characters in Mortal Kombat 4, Tanya and Sonya, are named after the sisters of Ed Boon, the game's co-creator.
Fujin is the god of wind in both Mortal Kombat 4 and Japanese mythology, similar to Raiden, the god of thunder, who was introduced in Mortal Kombat.
The home version of Mortal Kombat 4 included three exclusive playable characters: Noob Saibot, Meat, and Goro.
On July 31, 1998, Mortal Kombat 4, with the exception of the GBC version, was put on the infamous German index by the BPjS. For more information about what this means and to see a list of games sharing the same fate, take a look here: BPjS/BPjM indexed games.